This invention relates to mobile chairs and, more particularly, to an electrically driven mobile chair.
There have been known heretofore a variety of different self-propelled mobile chairs, including various types of electric wheelchairs controllable by the user in various ways, such as by operating a switch or steering control manually to control the supply of battery power to motors such as typically independent drive wheels at the sides of the chair.
For many purposes, such conventional electric wheelchairs are awkward and of such large size, complexity and cost as to render them essentially useless for certain situations, being poorly suited, for example, for use in closely confined quarters requiring close maneuvering and unable to shift sidewards or turn abruptly.
Further, there are many occupations and activities which require a person to be seated, such as in close proximity to a workbench, where it is desirable to be able to maneuver the chair toward and away from the work area and to turn the chair to one side or the other.
There are many individuals who have limited mobility or various disabilities which dictate the need for a highly maneuverable, self-propelled chair. It would also be desirable for such a mobile chair to be controlled other than by conventional hand-operated switches, steering arms or the like, so that one would not need to interrupt other manual activity.
Accordingly, it is an object of the invention to provide an improved self-propelled, self-contained mobile chair, and particularly, such a chair which is selectively driven by the user by postural shifting while seated upon the chair.
It is a further object of the invention to provide such a mobile chair which does not utilize conventional hand-operated switches, steering arms, or the like, and requires no manual operation of controls.
Another object of the invention is the provision of such a mobile chair which is extremely maneuverable and provides both translational and turning movement in response to such postural shifting.
A further object of the invention is the provision of such a mobile chair which provides a large surface area of contact with the surface upon which it is supported for improved weight distribution and efficient frictional rolling engagement of myriad surfaces.
Other objects of the invention include the provision of such a mobile chair which is light in weight and extraordinarily compact, which can maneuver in very close, confined areas, which is extremely easy to occupy and maneuver, and which requires little power for operation.
Briefly, a mobile chair of the invention comprises a frame carrying at its top a pivotally mounted passenger seat and captively mounting for rotation about various possible axes a relatively large sphere, which bears the principal weight of the chair and passenger. Auxiliary support is provided by casters surrounding the sphere. The frame has a battery and at least one drive motor for producing rotation of the sphere by means of a drive roller frictionally engaging the sphere. Postural movement of the seat provides power to the motor. Various arrangements allow sphere axis location for turning the chair.